title: Fabrication of nanogel core-silica shell and hollow silica nanoparticles via an interfacial sol-gel process triggered by transition-metal salt in inverse systems.
abstract: Nanogel (hydrophilic polymer nanoparticles) core-silica shell nanoparticles were successfully fabricated via hydrolysis and condensation reaction of tetraethoxysilane (TEOS). Transition-metal tetrafluoroborate-containing nanogels were used as templates for fabrication in inverse systems (cyclohexane as continuous phase). Magnetic, hollow silica particles were subsequently formed by removing the polymer core and converting iron salts to iron oxides via heat treatment. We propose that the formation of the core-shell morphology is induced by the promoted precipitation of silica species at the surface of nanogels due to the interaction between silica species and transition-metal tetrafluoroborate. The influence of the synthesis parameters (type and amount of salts, pH of the nanogels, and amount of TEOS) on the particle morphology was systematically investigated. The pore properties and specific surface area of the hollow silica particles could be modified by the varying the amount of salt.
authors.affiliation: College of Materials, Chemistry and Chemical Engineering and Department of Physics, Hangzhou Normal University, Hangzhou 310036, China. caozhihai@hznu.edu.cn
authors.forename: Zhihai
authors.initials: Z
authors.lastname: Cao
authors.forename: Liu
authors.initials: L
authors.lastname: Yang
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Yan
authors.forename: Yue
authors.initials: Y
authors.lastname: Shang
authors.forename: Quanlin
authors.initials: Q
authors.lastname: Ye
authors.forename: Dongming
authors.initials: D
authors.lastname: Qi
authors.forename: Ulrich
authors.initials: U
authors.lastname: Ziener
authors.forename: Guorong
authors.initials: G
authors.lastname: Shan
authors.forename: Katharina
authors.initials: K
authors.lastname: Landfester
mesh_terms: D005782:Gels / Q000138:chemical synthesis*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D028561:Transition Elements
chemical_list: D005782:Gels; D012821:Silanes; D028561:Transition Elements; C040733:tetraethoxysilane; D012822:Silicon Dioxide
keywords: Hollow silica particles; Magnetization; Nanogel core–silica shell nanoparticles; Transition-metal salt